The present invention relates to the perfumery and flavor industry. It concerns more particularly the use of a compound of formula (I) as perfuming or flavoring ingredient 
wherein R1 and R2 represent simultaneously or independently a linear or branched alkyl or alkenyl group containing 1 to 4 carbon atoms;
R3 represents a hydrogen, a cycloalkyl or a cycloalkenyl group, possibly substituted, a furanyl group, possibly substituted, a linear or branched alkyl or alkenyl group containing 1 to 12 carbon atoms, possibly substituted, or a linear or branched alkyl or alkenyl group containing 1 to 4 carbon atoms terminated by a carboxyl ester or amide group; and
R4 represents a hydrogen or a linear alkyl group containing 1 to 4 carbon atoms.
Substituents groups of R3 can be for example C1-C3 alkyl or alkenyl groups, an aromatic ring or C5-C7 cycloalkyl or cycloalkenyl groups, possibly substituted by methyl or ethyl groups.
Many 1,3-oxathianes and their use in the flavor and fragrance industry have been investigated for several years. The best known amongst these is 2-methyl-4-propyl-1,3-oxathiane, described in U.S. Pat. No. 4,220,561, which is very much appreciated in the flavoring industry for it sweet, passion fruit note.
Up to now, all the 1,3-oxathianes reported in the prior art and known to be useful in the perfuming or flavoring industry are mono substituted in position 4 of the ring or, at least, they carry a substituent in position 5 or 6 of the ring.
To the best of our knowledge, there are only six compounds of formula (I) reported in the prior art but no odor or flavor properties have been reported for any of them. Tetrahedron Lett., 2000, 41, 371-5 teaches the use of 2-[2-(4-methoxy-phenyl)ethenyl]-4,4-dimethyl-1,3-oxathiane and 4,4-dimethyl-2-(2-phenylethenyl)-1,3-oxathiane as chemical intermediates in cycloaddition-elimination reactions. Org. Magn. Reson., 1979, 12, 331-6 and Tetrahedron Lett., 1970, 8, 551-4 report studies on the cycle conformation of 2,2,4,4-tetramethyl-1,3-oxathiane, 2,4,4-trimethyl-1,3-oxathiane and 4,4-dimethyl-1,3-oxathiane. Finally, 2-(2-methyl-1-propenyl)-4,4-dimethyl-1,3-oxathiane is known only as a Chemical Abstract registry number, but is not described in the literature.
Surprisingly, we have now been able to establish that the compounds of formula 
as defined above, possess useful and surprising organoleptic properties, which render them very convenient for the perfume and flavor industry.
Preferred compounds of formula (I) are those of formula 
wherein R3 represents a hydrogen, a cycloalkyl or a cycloalkenyl group, possibly substituted, a furanyl group, possibly substituted, a linear or branched alkyl or alkenyl group containing 1 to 12 carbon atoms, possibly substituted, or a linear or branched alkyl or alkenyl group containing 1 to 4 carbon atoms terminated by a carboxyl ester or amide group; and
R4 represents a hydrogen or a methyl group.
Substituents groups of R3 can be for example C1-C3 alkyl or alkenyl groups, an aromatic ring or C5-C7 cycloalkyl or cycloalkenyl groups, possibly substituted by methyl or ethyl groups.
The odor and flavor properties of compounds of the invention appear as totally unexpected in view of the prior art with is totally silent with regard to the organoleptic behavior of their analogues.
The odor profile of the compounds of formula (II) appears to depend on the nature of the substituents R3 and R4. Frequently, the odor profile is of the herbaceous and sulfury type, in association with notes of the fruity, minty or aromatic herbs type. In other instances, the odor profile is of the sulfury type with notes of the animal/perspiration, woody, green or fruity type. Some compounds present odors of the herbaceous type, together with fruity, aromatic herbs type notes, or yet herbaceous or sulfury notes, together with fruity or aromatic herbs nuances.
Amongst the compounds of formula (II), 2-heptyl-4,4-dimethyl-1,3-oxathiane (odor profile: cassis, fruity, lemon, green, natural), 2-(5-methyl-2-furyl)-4,4-dimethyl-1,3-oxathiane (odor profile: cassis, herbaceous, sulfury, with exotic fruit, cassis, natural bottom notes), 4,4-dimethyl-2-propyl-1,3-oxathiane (odor profile: herbaceous-aromatic, parsley, thujonic, slightly lime and sulfury-buchu character) and 2,4,4-trimethyl-2-penthyl-1,3-oxathiane (odor profile: sweet, sugary, slightly onion but very natural, basil leaves, with basil, sage, tagetes, sulfury and natural bottom notes) are very much appreciated for their original odor profile.
Even more preferred are the 2-ethyl-4,4-dimethyl-1,3-oxathiane and 2-(2,4-dimethyl-3-cyclohexene-1-yl)-4,4-dimethyl-1,3-oxathiane. 2-Ethyl-4,4-dimethyl-1,3-oxathiane has an odor profile of the type herbaceous, sage, tagete leaves, cassis, wild mint, slightly sulfury type with an onion under note. This is a very natural and outstanding perfuming ingredient, possessing an unusual green, thyme note that adds a natural touch to the herbaceous note when used in compositions at low proportions.
2-(2,4-Dimethyl-3-cyclohexene-1-yl)-4,4-dimethyl-1,3-oxathiane has a multiodorant profile comprising green, natural, herbaceous, chervil, artemisia, tagete, sage nuances, is also very natural and confers to the herbaceous-aromatic compositions an improved impact and a very natural aspect, even at low concentrations.
The compounds of the invention can be used in a wide range of concentrations to create fragrance effects totally unexpected heretofore. The compounds of the invention can suit almost all the fields of modern perfumery. One can cite the applications in fine perfumery, namely in the creation of perfumes and colognes, wherein novel and original odor effects can be obtained.
The compounds of the invention can also be used in functional perfumery, namely to perfumed soaps, shower or bath gels, shampoos, body deodorants and antiperspirants, ambient air deodorants, liquid or solid detergents for textile treatment, detergent compositions or cleaning products for dishes or varied surfaces, or cosmetic preparations.
In these applications, the compounds according to the invention can be used alone, as well as mixed with other perfuming ingredients, solvents or additives commonly used in perfumery. The nature and variety of these co-ingredients do not require a more detailed description here, which would not be exhaustive anyway. In fact, a person skilled in the art, having a general knowledge, is able to choose them according to the nature of the product that has to be perfumed and the olfactory effect sought. These perfuming co-ingredients belong to varied chemical groups such as alcohols, aldehydes, ketones, esters, ethers, acetates, nitrites, terpenic hydrocarbons, heterocyclic nitrogen- or sulfur-containing compounds, as well as natural or synthetic essential oils. Many of these ingredients are listed in reference texts such as S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, N.J., USA, or more recent versions thereof, or in other similar books, or yet in the specialized patent literature commonly available in the art.
The proportions in which the compounds according to the invention can be incorporated in the different products mentioned above vary in a broad range of values. These values depend on the nature of the product that has to be perfumed and on the olfactory effect sought, as well as on the nature of the co-ingredients in a given composition when the compounds of the invention are used in admixture with perfuming co-ingredients, solvents or additives commonly used in the art.
In a general manner, the compounds according to the invention will be used in small amounts, typically at high dilution, owing to their strong odor impact.
For instance, concentrations from 0.01% to 5%, and preferably from 0.02% to 3%, by weight of these compounds, with respect to the perfuming composition in which they are incorporated, can be typically used. Much lower concentrations than these can be used when these compounds are directly applied for perfuming some of the consumer products mentioned above.
As previously mentioned, the compounds of the invention are also useful in the field of flavors, i.e. to impart taste to flavoring compositions and foods or beverages for example.
Their taste, which appears to be a function of the nature of the R3 and R4 groups, is generally of the herbal, hop type, in association with fatty or floral notes. Occasionally, woody, terpenic type notes together with spicy or fruity notes characterize the taste of some of the compounds of the invention. In particular the taste of 4,4-dimethyl-2-propyl-1,3-oxathiane is of the woody, terpenic, pepper type whereas 4,4-dimethyl-2-(1-methylbutyl)-1,3-oxathiane presents a terpenic, woody, black-currant, grapefruit flavor and 2-(2,4,4-trimethyl-1,3-oxathiane-2-yl)-acetamide possesses a herbal, hop, beer, sulfury type flavor.
In flavor applications, the compounds according to the invention will typically be used in concentrations of the order of 0.1 to 10 ppm with respect to the product into which they are incorporated. Much higher concentrations can be chosen when the compounds are used in concentrated flavors or flavoring compositions, intended to be incorporated in consumer products.
The compounds of the invention thus make it possible to confer, improve, enhance or modify the odor or taste of a consumer product, as well as of perfuming bases or concentrates, or yet flavor preparations and compositions.
The invention will now be described in further detail by way of the following examples, wherein the abbreviations have the usual meaning in the art and the temperatures are indicated in degrees centigrade (xc2x0 C.). The NMR spectral data were recorded with a 360 MHz machine in CDCl3, chemical displacements xcex4 being indicated in ppm with respect to the TMS as standard, and the coupling constant J being expressed in Hz. All the starting aldehydes are commercially available unless otherwise specified. 3-Methyl-3-mercapto-butanol was obtained according to B. J. Sweetman et al., J. Med. Chem., (1971), 14, 868.